Limits for scattering resonances in azimuthally inhomogeneous nanotubes

Resonant electromagnetic scattering has been optimized for angularly inhomogeneous nanotubes characterized by different surface admittances along the two complementary arcs. The optimal designs are substantially more efficient compared to the best homogeneous counterparts and the spatial distribution of the scattering power reveals the nature of the sustained resonances. In this sense, the reported scattering scores constitute limits for the response of that simple class of structures and can be employed as optimized components in a wide spectrum of photonic devices from wave transformers and field sensors to electromagnetic filters and optical lenses.

Leveraging Design Heuristics for Multi-Objective Metamaterial Design Optimization

Design optimization of metamaterials and other complex systems often relies on the use of computationally expensive models. This makes it challenging to use global multi-objective optimization approaches that require many function evaluations. Engineers often have heuristics or rules of thumb with potential to drastically reduce the number of function evaluations needed to achieve good convergence. Recent research has demonstrated that these design heuristics can be used explicitly in design optimization, indeed leading to accelerated convergence. However, these approaches have only been demonstrated on specific problems, the performance of different methods was diverse, and despite all heuristics being “correct”, some heuristics were found to perform much better than others for various problems. In this paper, we describe a case study in design heuristics for a simple class of 2D constrained multiobjective optimization problems involving lattice-based metamaterial design. Design heuristics are strategically incorporated into the design search and the heuristics-enabled optimization framework is compared with the standard optimization framework not using the heuristics. Results indicate that leveraging design heuristics for design optimization can help in reaching the optimal designs faster. We also identify some guidelines to help designers choose design heuristics and methods to incorporate them for a given problem at hand.

Longitudinal shock waves in a class of semi-infinite stretch-limited elastic strings

In this paper, we initiate the study of wave propagation in a recently proposed mathematical model for stretch-limited elastic strings. We consider the longitudinal motion of a simple class of uniform, semi-infinite, stretch-limited strings under no external force with finite end held fixed and prescribed tension at the infinite end. We study a class of motions such that the string has one inextensible segment, where the local stretch is maximized, and one extensible segment. The equations of motion reduce to a simple and novel shock front problem in one spatial variable for which we prove existence and uniqueness of local-in-time solutions for appropriate initial data. We then prove the orbital asymptotic stability of an explicit two-parameter family of piece-wise constant stretched motions. If the prescribed tension at the infinite end is increasing in time, our results provide an open set of initial data launching motions resulting in the string becoming fully inextensible and tension blowing up in finite time.

Introduction

The quantum realm exhibits phenomena that run counter to conventional logic. This chapter discusses the evidence from a particularly simple class of experiments: measurements or combinations of measurements which each have only two possible outcomes. It reviews the classical notions of logic and pins down where exactly they fail in the quantum realm. In particular, it highlights the importance of the order in which measurements are performed. The experimental evidence also calls for a critical review of the rules of probability theory. For these, too, this chapter identifies those which continue to hold in the quantum realm and those which need to be modi ed. Moreover, it introduces the pivotal concept of a ‘state’.

Competition for fluctuating resources reproduces statistics of species abundance over time across wide-ranging microbiotas

Across diverse microbiotas, species abundances vary in time with distinctive statistical behaviors that appear to generalize across hosts, but the origins and implications of these patterns remain unclear. Here, we show that many of these patterns can be quantitatively recapitulated by a simple class of resource-competition models, in which the metabolic capabilities of different species are randomly drawn from a common statistical ensemble. Our coarse-grained model parametrizes the intrinsic consumer-resource properties of a community using a small number of macroscopic parameters, including the total number of resources, typical resource fluctuations over time, and the average overlap in resource-consumption profiles across species. We elucidate how variation in these parameters affects various time series statistics, enabling macroscopic parameter estimation and comparison across wide-ranging microbiotas, including the human gut, saliva, and vagina, as well as mouse gut and rice. The successful recapitulation of time series statistics across microbiotas suggests that resource competition generally acts as a dominant driver of community dynamics. Our work unifies numerous time series patterns under one model, clarifies their origins, and provides a framework to infer macroscopic parameters of resource competition from longitudinal studies of microbial communities.

Black rubber and the non-linear elastic response of scale invariant solids

We discuss the nonlinear elastic response in scale invariant solids. Following previous work, we split the analysis into two basic options: according to whether scale invariance (SI) is a manifest or a spontaneously broken symmetry. In the latter case, one can employ effective field theory methods, whereas in the former we use holographic methods. We focus on a simple class of holographic models that exhibit elastic behaviour, and obtain their nonlinear stress-strain curves as well as an estimate of the elasticity bounds — the maximum possible deformation in the elastic (reversible) regime. The bounds differ substantially in the manifest or spontaneously broken SI cases, even when the same stress- strain curve is assumed in both cases. Additionally, the hyper-elastic subset of models (that allow for large deformations) is found to have stress-strain curves akin to natural rubber. The holographic instances in this category, which we dub black rubber, display richer stress- strain curves — with two different power-law regimes at different magnitudes of the strain.

Penerapan Terapi Modifikasi Perilaku dengan Teknik Shaping untuk Membentuk Kemandirian Anak

This study aims to intervene in children who are under the age category of toddlers with an attitude of independence in one kindergarten in Sampang, Madura. The method used in research is an experimental case study approach. Researchers provide interventions in the form of behavioral therapy, using Shaping techniques to bring up new behaviors that have not been displayed by children by providing reinforcement in every targeted behavior. This therapy can train children repeatedly with stages of modeling, imitating and taking the initiative to conduct targeted behavior interspersed with the reinforcement given. Children with this therapy will learn new behavioral patterns and learn slowly to apply and later become habitual behavior patterns. The independence formed by children here by maximizing limbs and moving the body to be able to themselves with simple class activities such as cursing shoes, taking and placing books, and taking the water they carry, which is usually through the teacher to fetch. The results of the application of shaping techniques for children are more learning and understanding that he must be independent at school and should not be accustomed to his behavior at home, even though the factors causing the independence are due to behavior patterns or treatment from his family (pampering).

Stamp technique- A novel approach in pediatric restorative dentistry

Stamp technique is new and novel method for restoring mainly class I and sometimes class II with accurate occlusal topography with near perfection. Since proprioceptors of stomatognatic system react sensibly under pressure as such occlusal discrepancy after direct restorations, even if it is minor, leads to discomfort to the patients. Eventually patients compensate by adapting to new habitual occlusal position, which causes serious long term craniomandibular disturbances. The restoration of Class I cavities and erosively damaged teeth was the main consideration for Stamp technique but can be utilized for class II cavity restorations where marginal ridge is intact. This technique is possible in teeth where preoperative anatomy of the tooth is intact and not destructed by carious lesion. The stamp technique is perfomed in order to get a precise tooth‑like restoration with an accurate functional occlusion. This case report presents a case of stamp technique for simple class I composite restoration. The intent was to replicate occlusal anatomy by making a copy of the original unprepared tooth structure to get absolute anatomy in few minutes.